U.S. patent application number 11/607329 was filed with the patent office on 2008-06-05 for fastening mechanism.
This patent application is currently assigned to Inventec Corporation. Invention is credited to Lin-Wei Chang.
Application Number | 20080130243 11/607329 |
Document ID | / |
Family ID | 39475455 |
Filed Date | 2008-06-05 |
United States Patent
Application |
20080130243 |
Kind Code |
A1 |
Chang; Lin-Wei |
June 5, 2008 |
Fastening mechanism
Abstract
The present invention discloses a fastening mechanism for
fastening a heat sink to the surface of an electronic device
mounted on a circuit board, the heat sink being provided with a
first positioning portion, the circuit board having two opposite
sides each formed with a notch. The fastening mechanism at least
includes a body for pressing the heat sink on the electronic
device, at least two bending portions corresponding in position to
and striding over the notches respectively, and at least two
snap-fit portions disposed at the end of each of the bending
portions and wider than the notches respectively, to enable
snap-fit engagement of the snap-fit portions with the edges of the
notches of the circuit board, thereby effectively fastening the
heat sink to the electronic device.
Inventors: |
Chang; Lin-Wei; (Taipei,
TW) |
Correspondence
Address: |
EDWARDS ANGELL PALMER & DODGE LLP
P.O. BOX 55874
BOSTON
MA
02205
US
|
Assignee: |
Inventec Corporation
Taipei
TW
|
Family ID: |
39475455 |
Appl. No.: |
11/607329 |
Filed: |
November 30, 2006 |
Current U.S.
Class: |
361/720 ;
257/E23.086 |
Current CPC
Class: |
H01L 23/4093 20130101;
H01L 2924/0002 20130101; H01L 2924/0002 20130101; H01L 2924/00
20130101 |
Class at
Publication: |
361/720 |
International
Class: |
H05K 7/20 20060101
H05K007/20 |
Claims
1. A fastening mechanism for fastening a heat sink to an electronic
device mounted on a circuit board, the heat sink being disposed
with a first positioning portion, the circuit board having two
opposite sides each disposed with a notch, the fastening mechanism
comprising: a body for pressing on the heat sink, the body having a
second positioning portion corresponding in position to the first
positioning portion; at least two bending portions disposed at both
ends of the body respectively, and corresponding in position to and
striding over the notches respectively; and at least two snap-fit
portions disposed at both ends of the bending portions
respectively, and wider than the notches respectively, for snap-fit
engagement with edges of the notches of the circuit board.
2. The fastening mechanism of claim 1, wherein the body is a metal
board.
3. The fastening mechanism of claim 1, wherein the first
positioning portion is a protruding post, and the second
positioning portion is a hole corresponding in position and shape
to the protruding post.
4. The fastening mechanism of claim 1, wherein the first
positioning portion is a hole, and the second positioning portion
is a protruding post corresponding in position and shape to the
hole.
5. The fastening mechanism of claim 1, wherein the second
positioning portion is centrally disposed in the body.
6. The fastening mechanism of claim 5, wherein a protruding portion
extending outward is centrally disposed in the body and is disposed
with the second positioning portion.
7. The fastening mechanism of claim 1, wherein the bending portions
extend and bend downward from both ends of the body.
8. The fastening mechanism of claim 1, wherein the snap-fit
portions extend outward from both ends of the bending portions.
9. The fastening mechanism of claim 1, further comprising an
operating portion disposed on an outer side of at least one of the
snap-fit portions.
10. The fastening mechanism of claim 9, wherein the operating
portion bends upward from an end of the snap-fit portion and
assumes a barb shape.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a fastening mechanism, and
more particularly, to a fastening mechanism for fastening a heat
sink to an electronic device.
[0003] 2. Description of the Prior Art
[0004] With continual advances in electronic technology, the
computation function of a computer is becoming more powerful, and
computation by a new generation chip is faster than it has ever
been before. As a result, chips in operation generate an increasing
amount of heat. To prevent heat generated by a chip in operation
from damaging the chip or shortening the life of the chip, a heat
sink is disposed on the chip as disclosed in the prior art, to
transfer any heat generated by the chip in operation to the heat
sink, and cool air is driven to the heat sink by fan to speed up
heat dissipation.
[0005] However, a conventional heat sink is typically fastened to a
chip by means of thermally conductive tape or adhesive, though
inefficiently; and the heat sink tends to loosen and thereby detach
because of computer-induced vibration or when the computer is
manually moved. Hence, a fastening mechanism is required to
efficiently fasten the heat sink to the chip so as to prevent the
heat sink from loosening and detaching.
[0006] Referring to FIG. 1, to solve the aforesaid problem, four
fasteners 1, such as four pins, are employed to fasten a heat sink
10 to a through hole 11 of a circuit board 13 and thus the heat
sink 10 is secured in position to a chip 12 mounted on the circuit
board 13; as a result, the heat sink 10 is unlikely to loosen and
detach, not to mention that heat dissipation by the heat sink 10 is
achieved.
[0007] Nonetheless, with a small area of contact between the
conventional fastener and a heat sink, no pressing force can be
uniformly and consistently applied, and in consequence a chip and
the heat sink cannot be pressed together evenly and tightly, and
thus heat dissipation of the chip is affected, not to mention that
the heat sink is seldom secured in position. In the aforesaid
situation, the heat sink is very likely to slide relative to the
chip when touched or subjected to vibration during a maintenance
operation, thus resulting in a decrease in the area of contact
between the heat sink and the chip, and affecting heat dissipation
of the chip. In addition, the aforesaid prior art entails using
four fasteners to secure in position the heat sink to the chip,
which is quite time-consuming and inconvenient to an assembly
worker.
[0008] Accordingly, an issue calling for urgent solution involves
providing a fastening mechanism for fastening a heat sink to a chip
conveniently and efficiently.
SUMMARY OF THE INVENTION
[0009] In light of the aforesaid drawbacks of the prior art, it is
a primary objective of the present invention to provide a fastening
mechanism for effectively fastening a heat sink to an electronic
device mounted on a circuit board.
[0010] Another objective of the present invention is to provide a
fastening mechanism which is easy to mount and dismount.
[0011] In order to achieve the above and other objectives, the
present invention provides a fastening mechanism for fastening a
heat sink to a surface of an electronic device mounted on a circuit
board, the heat sink being disposed with a first positioning
portion, the circuit board having two opposite sides each disposed
with a notch, the fastening mechanism comprising: a body pressing
on the heat sink, and having a second positioning portion
corresponding in position to the first positioning portion; at
least two bending portions disposed at both ends of the body
respectively, and corresponding in position to and striding over
the notches respectively; and at least two snap-fit portions
disposed at both ends of the bending portions respectively, and
wider than the notches respectively, for snap-fit engagement with
edges of the notches of the circuit board.
[0012] The body is a metal board. The first positioning portion and
the second positioning portion, both of which correspond in
position to each other, are a protruding post and a hole
respectively. Preferably, the second positioning portion is
centrally disposed in the body. A protruding portion extending
outward is centrally disposed in the body. The second positioning
portion is disposed in the protruding portion. The bending portions
extend and bend downward from both ends of the body. The snap-fit
portions extend outward from both ends of the bending portions.
Selectively, the fastening mechanism further comprises an operating
portion disposed on an outer side of at least one of the snap-fit
portions, and the operating portion bends upward from the end of
the snap-fit portion and assumes a barb shape.
[0013] Compared to the prior art, the present invention discloses a
fastening mechanism, wherein two bilaterally disposed snap-fit
portions of the fastening mechanism are snapped to a circuit board,
and a snap-fit force allows the body of the fastening mechanism to
press on a heat sink, thus fastening the heat sink to an electronic
device efficiently. In addition, dismounting the fastening
mechanism entails mere separation of the snap-fit portions from the
circuit board, and thus both a mounting operation and a dismounting
operation are made simpler.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 (PRIOR ART) is an exploded view showing how to fasten
a heat sink to a chip mounted on a circuit board;
[0015] FIG. 2 is an exploded view showing how to fasten a heat sink
to an electronic device mounted on a circuit board with a fastening
mechanism of a preferred embodiment of the present invention;
[0016] FIG. 3 is a cross-sectional view of FIG. 2; and
[0017] FIG. 4 is a schematic view showing how to dismount a
fastening mechanism of a preferred embodiment of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] The following specific embodiment is provided to illustrate
the present invention. Others ordinarily skilled in the art can
readily gain an insight into other advantages and features of the
present invention based on the contents disclosed in this
specification.
[0019] Referring to FIG. 2, which is an exploded view showing how
to fasten a heat sink 22 to an electronic device 20 mounted on a
circuit board 2 with a fastening mechanism 3 of the present
invention. The heat sink 22 comprises a first positioning portion
23. Two opposite sides of the circuit board 2 are disposed with a
notch 24 each. The electronic device 20 is, for example, a
semiconductor chip coated with thermally conductive adhesive 21 for
transferring to the heat sink 22 any heat generated by the
electronic device 20 with a view to speeding up heat dissipation.
The fastening mechanism 3 comprises a body 30, at least two bending
portions 31, and at least two snap-fit portions 32. The body 30
presses on the heat sink 22. The bending portions 31 are disposed
at both ends of the body 30 respectively. The snap-fit portions 32
are disposed at both ends of the bending portions 31
respectively.
[0020] The fastening mechanism 3 is, for example, a metal board, or
any equivalent panel-shaped component characterized by thermal
resistance and rigidity. Besides, the fastening mechanism 3 enables
an increase in heat dissipation area of the electronic device
20.
[0021] The body 30 comprises a second positioning portion 301
corresponding in position to the first positioning portion 23. The
body 30 presses on the heat sink 22, and thus the heat sink 22 is
pressed against the electronic device 20. In this embodiment, the
second positioning portion 301 is a hole, and the first positioning
portion 23 is a protruding post. The second positioning portion 301
and the first positioning portion 23 correspond in position to each
other and thereby couple with each other, so as to secure in
position the body 30 to the heat sink 22 with a view to preventing
the heat sink 22 from sliding. The second positioning portion 301
is, approximately, centrally disposed in the body 30. A protruding
portion 302 extending outward is centrally disposed in the body 30.
The second positioning portion 301 is disposed in the protruding
portion 302.
[0022] A point to note is that, although this embodiment uses a
hole as the second positioning portion 301 and a protruding post as
the first positioning portion 23, persons ordinarily skilled in the
art obviously know that any protruding post protruding from the
surface of the body 30 and corresponding in position to the first
positioning portion 23 exemplified by a hole can be formed on the
body 30 by stamping, without being limited by the description of
this embodiment. Of course, the shape and the position of the
protruding portion 302 are not limited by this embodiment
either.
[0023] The bending portions 31 correspond in position to and stride
over the notches 24 respectively; also, the bending portions 31
extend and bend downward from both ends of the body 30. In this
embodiment, the bending portions 31 extend and bend downward 90
degrees from both ends of the body 30, and the number of the
bending portions 31 is two. However, in other embodiments, the
bending portion 31 extend and bend downward 90 degrees
approximately from both ends of the body 30, and at least one
bending portion 31 and one snap-fit portion 32 extend from the
protruding portion 302 so as to enhance snap-fit engagement.
[0024] The snap-fit portions 32 are wider than the notches 24, for
snap-fit engagement with the edges of the notches 24 of the circuit
board 2. In this embodiment, the snap-fit portions 32 extend
outward from both ends of the bending portions 31 and assume a T
shape or any other shapes.
[0025] The fastening mechanism 3 further selectively comprises an
operating portion 33 disposed on an outer side of at least one of
the snap-fit portions 32. In this embodiment, the operating portion
33 bends upward from the end of the snap-fit portion 32 and assumes
a barb shape, and thus the operating portion 33 assumes a U shape
approximately so as to avoid concentration of stress.
[0026] Referring to FIG. 3, which is a cross-sectional view showing
how to mount the fastening mechanism 3 of the present invention,
coupling the second positioning portion 301 to the first
positioning portion 23 and snap-fit engagement of the snap-fit
portions 32 with the edges of the notches 24 of the circuit board 2
allow the body 30 to press on the heat sink 22 and thereby firmly
fasten the heat sink 22 to the electronic device 20, and in
consequence a mounting operation can be quickly performed without
using a tool.
[0027] Referring to FIG. 4, to dismount the fastening mechanism 3
from the circuit board 2, a user may use a tool 4, such as a
slotted screwdriver, to actuate the operating portion 33, for
example, pulling the operating portion 33 outward to separate the
bending portion 31 from the notch 24 and thereby separate the
snap-fit portion 32 from the bottom of the circuit board 2, thus
dismounting the fastening mechanism 3 from the circuit board 2. Of
course, the user may choose to pull by hand the snap-fit portion 32
from the bottom of the circuit board 2 so as to separate the
snap-fit portion 32 from the bottom of the circuit board 2,
depending on the structural strength of the fastening mechanism 3
designed to work with an intended heat sink. For instance, in the
event that the fastening mechanism 3 is thin and of little
structural strength, the fastening mechanism 3 can be dismounted by
hand. However, in the event that the fastening mechanism 3 is of
considerable structural strength, a slotted screwdriver or any
other appropriate tool may be required to dismount the fastening
mechanism 3.
[0028] Accordingly, as disclosed in the present invention, a
fastening mechanism achieves snap-fit engagement with a circuit
board by means of snap-fit portions disposed at both ends of the
fastening mechanism. Also, as disclosed in the present invention, a
body of the fastening mechanism presses on a heat sink and thus the
heat sink is effectively fastened to an electronic device. As a
result, the present invention prevents the heat sink from getting
loosened under an external force. In addition, as disclosed in the
present invention, to dismount the fastening mechanism, a user may
actuate an operating portion and separate the corresponding
snap-fit portion from the circuit board, or the user may actuate a
snap-fit portion and separate the snap-fit portion from the circuit
board, thus allowing the user to perform a mounting operation and a
dismounting operation conveniently.
[0029] The aforesaid embodiment merely serves as the preferred
embodiment of the present invention. It should not be construed as
to limit the scope of the present invention. Hence, any other
changes can be made in the present invention. It will be apparent
to those ordinarily skilled in the art that all equivalent
modifications or changes made, without departing from the spirit
and the technical concepts disclosed by the present invention,
should fall within the scope of the appended claims.
* * * * *